President Trump and first lady Melania Trump walk and wave during his inaugural parade. (Jonathan Newton/The Washington Post)

Just after noon, as Donald Trump was sworn in as president, James Kelly was on the Mall, more than half a mile away, bouncing his 10-year-old son on his shoulders and shouting.

“He did it! He did it!” said Kelly, a doctor who drove with his two sons from Easton, Md., the three of them holding signs that together read, “Drain the Swamp!”

The traditional 21-gun salute began; just a few blocks and several security gates away, at a protest outside Union Station, the crack of the guns stopped conversation cold. Rahima Schwenkbeck, 32, a graduate student from Washington, frowned and waved at the Capitol.

“Goodbye, America: It was nice knowing you,” she said. “I’ll miss my civil liberties.”

The 58th presidential inauguration — like the 2016 campaign that wrought it — was an often awkward meeting of extremes. Yet it also marked the peaceful transition of power from a party that had won more votes to a party that had won fewer for just the fifth time in the country’s history.

(Erin Patrick O'Connor,Whitney Leaming,Thomas Johnson/The Washington Post)

For the victors, Washington was the site of a day-long end-zone dance, the culmination of what was once considered Trump’s impossible dream. For the demonstrators, it was a day to start what they hope will be four years of unceasing resistance.

For everyone in the nation’s capital Friday, the day was a montage of jarring, discordant imagery, the sidewalks packed with jubilant Trump supporters, weeping and irate protesters, and battle-ready police officers and members of the National Guard.

Flag-waving “bikers for Trump” glared at Black Lives Matter protesters dressed in chains. Suit-clad Trump supporters narrowed their eyes at signs with jokes about the new president’s hair, hands and predilections.

They all eyed one another curiously, with caution — and sometimes across barricades that kept them at shouting distance.

And sometimes, they all just blended.

Before 8 a.m., Kenny Kerns, 53, an electrical lineman from Accokeek, Md., found himself at Dupont Circle, where advocates for marijuana legalization handed out 4,200 joints to protest Trump’s election.

(Whitney Leaming/The Washington Post)

Kerns wore a football jersey — “T-R-U-M-P” on the back, with “45” on the front. He said he was there because his son, Frank, 22, wanted to get some pot, and neither voiced any concern that the new president’s nominee for attorney general is opposed to legalization.

Trump’s ability to communicate in terms he understood, Kerns said, was what drew him like no other politician ever has.

“When I saw this fellow talk on TV,” Kern said, “he talked like I could understand him. When he said ‘anchor baby,’ I understood. It felt like it came from inside of him, like he wasn’t sugarcoating anything. And if he can’t change things, no one can.”

The joint giveaway was a remnant of the America that gave up power at noon, as former president Barack Obama and his family flew out of town. The day was packed with opportunities for progressives to rally, organize and protest.

For Mary Stanfield, 26, the day began with a meandering “Occupy Inauguration” event at an area many call Malcolm X Park. Next to a statue of Joan of Arc, which had been wrapped in a red sash with the legend “Resist,” a few dozen activists talked over a guitar-strumming singer.

“I checked Facebook in the morning, and it was like: You have 15 events today,” Stanfield said. “We decided to focus on the ones that seem safe. We want to avoid unrest.”

Molly Miller, 25, Stanfield’s childhood friend, had come from Texas wearing a jacket festooned with Hillary Clinton buttons. “We won the majority,” she said. “We won a historic majority. So it’s not about what Democrats need to change; it’s about a system that’s broken.”

There would be unrest in small pockets of downtown. Without disrupting the inauguration itself, some black-clad protesters broke away from rally sites and smashed windows, upended trash cans and set small fires.

The vast majority of protesters, however, felt solidarity growing as power slipped away. Adam Shuck, 30, marched with fellow members of Democratic Socialists of America as noon approached. He had voted for Jill Stein, the Green Party’s candidate for president, in Pennsylvania. But he had grown less sure about that vote since the election.

“I was shocked at how weak the Clinton campaign turned out to be,” he said. That weakness, in Sharp’s view, propelled Trump’s victory. “I’m a white, gay man,” he said. “I don’t feel particularly vulnerable. The first thing I’m worried about is the safety of my Muslim neighbors in Pittsburgh.”

The tension that infused the day, the possibility of protests and clashes, created a sense of drama that was part of what compelled Kevin Sembrat, 54, to drive with his son from central New Jersey.

A Trump supporter, Sembrat wanted to see his man take the oath. But he said he also wanted to bear witness to whatever havoc Trump’s ascent would stir.

“It’s like a car race,” the copywriter said as he waited in line to enter the Mall. “You want to see if something bad happens. You hate to see the driver wrecking his car, but you can’t turn away.”

By mid-afternoon, there was havoc, contained around Franklin Square and the surrounding blocks, where fires were set in newspaper boxes and a stranded limousine. But only a handful of Trump supporters, and relatively few protesters, stood around to gawk. More protesters joined the marches crossing from Union Station to McPherson Square, where hot vegan food was free and activists such as Michael Moore gave speeches.

Stephanie Walton, 51, watched with a widening grin as one demonstration moved along New York Avenue. She had come to the city from California to join the protests and then the Women’s March on Washington. Before last year, when she protested the Trump victory, she had not demonstrated since Michael Dukakis lost the 1988 election.

“Can I join you?” she asked a protester when the march reached her. She lifted her iPhone and turned the camera on herself, spinning around and reporting for an audience back home.

“This is history!” she said. “This is a party!”